Material for filling cracks or gaps and methods of applying same

ABSTRACT

Flexible filler for filling cracks, gaps or holes in masonry or a rendered finish on masonry, comprising a mixture of an acrylic caulk bulked up with a finely divided particulate material of a size to match the roughness of the surface around the crack gap or hole to be filled. The caulk and particulate material are mixed thoroughly to form a homogeneous mixture which is packed into a cylindrical cartridge having a nozzle through which the mixture can be forced when needed. Apparatus by which the contents of a conventional acrylic caulk filled cartridge can be replaced with the improved filler, comprising a holder for supporting the cartridge, means for forcing out the caulk contents of the cartridge into a container, means for adding particulate material to the caulk in the container, means for mixing the caulk and particulate material to form a homogeneous mixture, means for refilling the cartridge with at least some of the homogeneous mixture and means for reinserting a plunger into the cartridge, for subsequently forcing the filler from the cartridge to fill a crack, gap or hole.

FIELD OF INVENTION

[0001] This invention concerns materials of a paste-like composition which can be used to fill cracks in brickwork or rendered surfaces of a building or to fill gaps between window or door frames and surrounding brickwork which may be rendered, and can be painted over.

BACKGROUND TO THE INVENTION

[0002] It is known to form a paste-like filler material by mixing a cement based powder with water and to fill cracks in plasterboard, brickwork and rendered finishes, with this mixture before painting. Conventionally such filers possess little or no flexibility once they have set hard and tend to shrink and crack, on drying, especially when employed to fill wide and deep cracks.

[0003] Additionally such fillers are designed to dry to a smooth finish, since their primary application is in filling cracks in smooth plaster. When used to fill cracks in rough or textured surfaces, the smooth line of the filled crack will tend to be visible even after painting with a textured paint such as SANDTEX™.

[0004] When door and window frames are made to be fitted to existing openings they are conventionally manufactured undersize to allow the frame to be introduced into the opening. The resulting gap between the frame and the brickwork is conventionally filled using a flexible silicone sealant. Whilst the flexibility and water repellent characteristics of such materials are excellent properties for such fillers to possess, the presence of the silicone component means that the filled gap cannot be overpainted. Therefore whilst silicone based paste-like fillers could be used to fill cracks in brickwork, plasterwork or rendering, the presence of the silicon, means the filled crack will not accept paint and since it is desirable to provide a filler which will allow the repaired surface to be painted with a protective weather-proofing coat of paint, silicone based fillers are not suitable.

OBJECT OF THE INVENTION

[0005] It is an object of the present invention to provide a flexible material which can be used to fill cracks and gaps in masonry, especially in a render coat on brickwork or blockwork which is to be painted, and gaps around door and window frames in masonry walls, especially where the latter are to be painted or are (or are to be) rendered and the render coat is to be painted.

[0006] It is another object of the present invention to provide a method of mixing materials to form a flexible filler which is suitable for filling cracks and gaps as aforesaid.

[0007] It is an object of the present invention to provide a method of filling cracks or gaps as aforesaid prior to the application of a coat of paint.

SUMMARY OF THE INVENTION

[0008] According to one aspect of the present invention a flexible filler for filling cracks, gaps or holes in masonry or a rendered finish on masonry comprises a mixture of an acrylic caulk and finely divided particulate material.

[0009] The caulk may be a product known as Evo-stick Decorators Flexible Caulk as manufactured and supplied by Evode Ltd.

[0010] Other similar caulking compounds are manufactured and supplied by Dow Corning.

[0011] The finely divided particulate material may comprise sand (either soft sand or silver sand), or plastics material in the form of particles of appropriate size to match the material of the surface to be filled, or finely chopped glass fibre strands or micospheres of glass.

[0012] The plastics material could be polyethylene or polypropylene and numerous other commonly used plastics materials. These can be obtained in granular form for injection moulding. If the granules are too coarse they would have to be ground down to the appropriate size.

[0013] The precise proportions of caulk and particulate material can be established by experiment. A preferred ratio when using moist sand is 300 grams of moist sand to 310 ml of Evo-stick Decorators Flexible Caulk. The plastics materials would need to be added in the equivalent volume ratio.

[0014] According to another aspect of the invention appropriate proportions by weight or volume of caulk and moist sand are mixed thoroughly to form a homogeneous mixture and the mixture is packed into a cylindrical tube having a nozzle through which the mixture can be forced by pressurising the contents of the tube.

[0015] Preferably the filling of the tube is achieved so as not to entrap air bubbles in the mixture.

[0016] Where sand is employed as the particulate material it has been found preferable to employ moist sand rather than dry sand, since adding dry sand to a flexible acrylic caulk appears to draw moisture from the acrylic causing lumps to form, instead of a homogeneous mixture of separate sand particles evenly distributed through the caulk.

[0017] It is important that the homogeneity of the mixture is maintained up to application and a preferred method comprises the steps of mixing flexible acrylic caulk and moist sand in correct proportions, stirring thoroughly, and packing the mixture in a tube, from which it can be forced through a nozzle as required, just prior to application.

[0018] Discharge from the tube may be achieved in any convenient manner, as by applying air pressure to the end of the tube remote from the nozzle as required, or more preferably providing a closely fitting piston in the tube to the rear of the caulk-sand mix and either applying air pressure to the rear of the piston to pressurise the material ahead of the piston, or attaching a manually operable drive to incrementally force the piston along the tube by movement of a finger operated trigger operating the drive to the piston through a one-way clutch, thereby to force the mixture out of the nozzle.

[0019] By squeezing the trigger repetitively and regularly a relatively thick viscous material, such as the mixture proposed by the invention, can be forced out of the nozzle in a substantially continuous steady flow.

[0020] Preferably the cross-section of the opening in the end of the nozzle from which the mixture issues, can be adjusted in size to allow for work on larger or smaller cracks, gaps or holes.

[0021] In one method according to the invention the nozzle is located close to one end of a crack or gap which is to be filled, and after squeezing the trigger, or operating the pressurising system, to cause the mixture of flexible caulk and particles to exit therefrom, the tube and nozzle is moved slowly along the crack or gap so that the mixture is forced into the crack,

[0022] Preferably any crack, gap or hole is prepared prior to application of the mixture, as by brushing and if necessary by gouging or routing so as to widen the entrance to the opening that is to be filled to assist in filling it with the mixture.

[0023] By positioning the nozzle substantially perpendicular to the surface of a surface which contains a crack, gap or hole, the mixture will tend to be forced deep into the opening.

[0024] Where the opening has a significant length as in cracks in rendering or gaps around window and door frames, it is found that the mixture is most easily applied if the nozzle is held at a small angle to the perpendicular to the surface and points away from the direction of movement along the crack.

[0025] Any surplus mixture which remains as a bead along the entrance to the crack and/or either side of the crack can be removed using a spatula or knife, typically by forcing the mixture deeper into the opening.

[0026] Application of the material is finished off using a wet sponge or brush to remove any excess from the surface around or on either side of the opening, and to enhance the rough surface to the material in the opening.

[0027] Following this procedure will avoid leaving a band or stripe proud of the rendered surface.

[0028] More importantly, the surface of the material at the entrance to the opening will be rough due primarily to the presence of the particulate material in the mixture filling the opening, unlike conventional fillers, which leave a smooth surface to the material filling the opening.

[0029] Although the width of a crack may only be of the order of one or two millimetres, depending on the lighting conditions (e.g. direction of sunlight illuminating the repaired surface) even after painting, the smooth surface (resulting from the use of conventional fillers) will be visible in the painted finish. On the other hand, when a textured acrylic caulk is employed (as proposed by the present invention), the rough (or textured) surface of the material filling the crack blends with the rough finish on the remainder of the surface and the line of the crack cannot be seen so readily.

[0030] According to another aspect of the invention apparatus is provided adapted to hold a standard conventional acrylic caulk filled cartridge, to allow the contents of the cartridge to be removed for mixing with particulate material and then replaced in the cartridge ready for application.

[0031] The apparatus may comprise a cartridge holder, a guillotine or scissors based cutting device for removing the sealed end of the nozzle, a push rod plunger and drive therefor adapted to act on the movable closure at the far end of the cartridge to force the acrylic caulk through the nozzle, a first reservoir adapted to receive the ejected acrylic caulk, an elongate pin and drive therefor adapted to enter the nozzle, after the cartridge has been emptied, to push the closure back along the cartridge in the opposite direction and out of the far end thereof, a second reservoir capable of receiving particulate material, for mixing with the caulk ejected from the cartridge, a mixing aid such as a paddle or helical screw and a drive therefor to rotate the mixing aid and thoroughly mix the acrylic caulk and the particulate material, and a feed by which the mixture can be conveyed to and forced into the open far end of the empty cartridge until it is full.

[0032] The closure can be inserted into the open end of the cartridge after it has been re-filled, and can be pushed therealong until the contents are compacted, ready to be discharged through the nozzle, using for example a conventional trigger operated device.

[0033] The apparatus may include a device for forcing the closure into the open end of the cartridge after filling.

[0034] The drives may be electrically powered as by motors or solenoids, but in the case of apparatus intended to be used by the tradesman or building worker on site, the drives are preferably manually operable, as by turning a handle or wheel or pushing a lever.

[0035] Preferably the apparatus includes a device for closing off the open end of the nozzle, as the cartridge is repacked, to prevent the contents of the cartridge being forced out of the open end of the nozzle as the cartridge becomes filled during the re-filling step.

[0036] The second reservoir may comprise a hopper into which particulate material can be poured, when required, or may be a cylindrical member into which a piston can be inserted to push the particulate material therefrom, for mixing with the acrylic caulk.

[0037] If water is to be added to the particulate material, it is important that it is added to that material well before the particulate material is added to the ejected contents of the cartridge, and to this end a valve may be provided to allow water to be introduced into the second reservoir or into a passage between the second reservoir and a region in which the contents of the two reservoirs are mixed, along which the particulate material flows for mixing with the contents of the first reservoir.

[0038] The mixing may take place in the first reservoir, in which event the mixing aid is adapted to operate within that reservoir.

[0039] Alternatively the contents of the first and second reservoirs may be forced into a mixing region in which the mixing aid operates, and the homogeneous mixture is forced from there into the empty cartridge.

[0040] A mixing aid may be provided for mixing the particulate material and water so as to ensure that the water is evenly spread throughout the mass of particulate material, before it is mixed with the acrylic caulk.

[0041] In one arrangement which enables a single mixing aid to be used, the water may be supplied to the mixing region before, after or during the supply of particulate material alone thereto, and the mixing aid therein is employed to mix the water and particulate material before the caulk is introduced into the region, for mixing therewith.

[0042] The advantage of mixing the acrylic caulk and particulate material just prior to application is that the particulate material will still be in suspension and substantially evenly spread throughout the material in the cartridge, and remains so as the mixture is applied to crack(s) etc. This is important, since the advantage of the invention will be lost if the particulate material is not evenly spread throughout the material in the cartridge, thereby causing some of the mixture to be discharged with inadequate proportions of particulate material, which could leave a smooth surface to the material in the opening.

[0043] It is possible that if the particulate material is mixed with the caulk during initial manufacture and filling of the cartridge and the cartridge is left stored in one position for any length of time, especially if stored in a high ambient temperature, migration of the particulate material under gravity within the cartridge may occur. This can produce a concentration of particulate material in one region and depletion in another within the cartridge. This could be a problem if the acrylic material becomes less viscous with elevated temperatures and if the filled cartridge were to be subjected to elevated temperatures as can occur in a warehouse or builders merchants store.

[0044] In general, shaking or vibrating the filled cartridge may not be sufficient to redistribute the particulate material, prior to application, although if the acrylic material can be made less viscous by heating, it may be sufficient to heat and vibrate the cartridge at the point of sale to the end user.

[0045] An alternative and more preferable solution may be to select a particulate material that has a density which is substantially the same as the acrylic material, so that there will be less tendency for migration and concentration/depletion occurring within the material in the cartridge during storage. This could enable the cartridges to be filled with the mixture of acrylic caulk and particulate material during initial manufacture—as may be preferable. Examples are polypropylene and polyethylene.

[0046] The material proposed by the invention allows cracks, gaps or holes in mortar or other rendered coatings to be filled prior to overpainting, so as to be generally invisible, after painting.

[0047] However it is prepared, the preferred method of application of the material proposed by the invention is under pressure from a nozzle. This ensures that the proposed material is forced deep into an opening, so that there is less tendency for the material to shrink into the opening, or itself crack or craze, as it cures.

[0048] Whilst the new material proposed herein is preferably applied under pressure via a nozzle so as to penetrate deep into openings, it may be applied alternatively using a spatula or filler knife, in which event the mixture may be contained in a tub from which it can be scooped by the spatula or knife blade. In this event the tub is preferably resealable and preferably air can be completely evacuated from the tub when it is sealed (and from the contents remaining in the tub after use) to prevent the acrylic material from curing, as it will do if exposed to air.

[0049] Alternatively the mixture may be contained in a squeezable tube similar to that used in relation to toothpaste. Such a tube may be systematically squeezed to move the mixture from one end to another to mix the caulk and particulate material to a smooth paste prior to use.

[0050] It is also a property of the material proposed by the invention, that by bulking the acrylic caulk with particulate material, especially sand, the resulting mixture has considerably more body to it than does the basic caulk, so that the resulting mixture is thicker in consistency and will tend to remain where it is located in a crack, gap or hole, to a greater extent than is the case if the acrylic caulk alone is employed as the filler.

[0051] Whilst of primary use in filling cracks in render coats prior to overpainting the repaired render coat, the material proposed by the invention and the methods of applying same and filling cartridges for nozzle application under pressure, may be utilised for filling gaps between window and door frames and surrounding brickwork, especially where the brickwork is rendered (or to be rendered) with material such as a mixture of sand and cement which will produce a textured or rough surface. The advantage is that the filled gap can then be overpainted when the render coat is painted, and unlike conventional silicone based fillers, (typically used to in-fill gaps between door and window frames), the filled gap will not be visible, since its textures surface will blend with the textured surface of the render coat.

[0052] As employed herein the term brickwork is intended to include within its scope blockwork or any other wall construction which is capable of being rendered as by a sand and cement mix.

[0053] The invention will now be described by way of example with reference to the accompanying drawings, in which:—

[0054]FIG. 1 illustrates a typical cartridge dispenser which is employed in the method of the invention,

[0055]FIG. 2 illustrates how the plunger can be removed from the cartridge to allow it to be refilled, and

[0056]FIG. 3 illustrates diagrammatically how the contents of the cartridge can be mixed and then dispensed into the empty cartridge.

[0057] In FIG. 1 a standard cartridge dispenser is shown comprising a cylindrical sleeve 10 open at the rear end 12 and closed at the front 14 by an end cap to which a tapering nozzle 16 is fitted typically by securing onto a threaded nipple 17 (see FIG. 2) in the centre of the end cap 14. The smaller diameter end of the nozzle can be cut to size when the cartridge is first used, to govern the size of the opening through which fluid contents are to be forced. A closure cap 18 is provided to allow the open end of the nozzle to be re-sealed if not all the contents of the cartridge are dispensed at the outset.

[0058] Prior to initial filling (during manufacture) a closure 20 is pushed into the open rear end 12 after the sleeve 10 has been filled with the material which is to be stored in the cartridge. The closure 20 is a tight sliding fit in the sleeve.

[0059] Initial filling is typically achieved through the nipple in the end cap 14, which is thereafter sealed.

[0060] The contents of the sleeve can be forced out by pushing the closure 20 towards the front end of the cartridge, so driving fluid material ahead of it, through the nozzle 16. The closure 20 therefore serves the dual purpose of closing the rear end of the sleeve and acting as a piston to drive out (dispense) material from the nozzle. However, when the sleeve has been fully evacuated the closure 20 is now at the front end 14 of the sleeve 10.

[0061] In order to re-use the cartridge, it is necessary to remove the closure 20 and this is best achieved by a metal push rod 22 (see FIG. 2). The rod is inserted through the nozzle 16 (or nipple 17 if the nozzle has been removed), and by pushing in the direction of arrow 24 (see FIG. 2), the closure 20 is forced out of the open end 12 of the sleeve 10.

[0062] In accordance with the invention, a pre-filled cartridge containing a proprietary acrylic caulk is first emptied, the acrylic caulk is mixed thoroughly with particulate material and if desired a liquid such as water, and then the cartridge is re-filled with the mixture ready for use.

[0063] Referring to FIG. 3, a mixing chamber 26 is provided with a first filling point/reservoir 28 into which the acrylic caulk from the pre-filled cartridge is dispensed by forcing it out of the pre-filled cartridge in known manner. A second filling point/reservoir 30 is filled with dry particulate material such as sand or ground-up plastics material from a box or bag 31.

[0064] Acrylic flows into the chamber 26 via feed 32 and particles via feed 34.

[0065] In the chamber is a helical screw 36 which is rotated by a drive 38. The latter may be a handle or wheel which can be turned by hand, or an electric motor or a shaft and coupling to which a power tool such as a motorised drill or screwdriver can be temporarily attached, to rotate the shaft and screw to thoroughly mix the contents of the chamber.

[0066] Valves are provided at 40, 42, 44 and 46 to control the inflow of material from 28 and 30 and the outflow of mixed material from 26 to a filler reservoir 48 and the outflow of mixed material from 48, respectively.

[0067] In use, after thoroughly mixing in 26 the mixture is released into the intermediate (filler) reservoir 48, the empty cartridge 10 is positioned below valve 46 and after opening 46, the mixture flows into the upper open end 12 of the cartridge.

[0068] In order to expel air ahead of the fill, the nozzle 16 is preferably replaced before the cartridge is filled, and initially the cap 18 is left off. As soon as the mixture appears at the end of the nozzle, the cap can be put in place (as shown in FIG. 3), to prevent further loss of mixture, and filling can continue.

[0069] When the mixture is within 3 cms or so of the upper open end 12, valve 46 is closed, and the closure (plunger) 20 is fitted into the end of the cartridge. Thereafter, the contents can be dispensed from the cartridge in manner known per se, after removing the cap 18, by pushing the closure 20 further into the cartridge 10, using a conventional trigger operated mechanism.

[0070] Since it has been found desirable to add water to the mixture in 26, a third filler point 50 is provided in the chamber 26 for admitting water from a tap 52 or water reservoir (not shown). If the latter, a further valve (not shown) is required to control the inflow of water into 50. 

1.-46. (Cancelled).
 47. A flexible filler by which cracks, gaps or holes in masonry or a rendered finish can be filled prior to painting so as to hide the existence of the crack, gap or hole, comprising a mixture of an acrylic caulk and finely divided particulate material of a size to match the roughness of the surface around the crack gap or hole to be filled, wherein the caulk and particulate material are mixed thoroughly to form a homogeneous mixture and the mixture is packed into a tube having a nozzle through which the mixture can be forced by pressurising the contents of the tube.
 48. A filler as claimed in claim 47 wherein the finely divided particulate material comprises sand.
 49. A filler as claimed in claims 47 wherein 300 grams of moist sand is mixed with to 310 ml of Decorators Flexible Caulk.
 50. A filler as claimed in claim 47 wherein the particulate material comprises particles of plastics material.
 51. A filler as claimed in claim 50 wherein the plastics material is polyethylene or polypropylene.
 52. A filler as claimed in claim 47 wherein the particulate material comprises finely chopped glass fibre strands.
 53. A filler as claimed in claim 47 wherein the particulate material comprises microspheres of glass.
 54. A method of creating a flexible filler by which cracks, gaps or holes in masonry or a rendered finish on masonry can be filled prior to painting so as to hide the existence of the crack, gap or hole, comprising the steps of mixing flexible acrylic caulk and particulate material of a size to match the roughness of the surface around the crack, gap or hole, and in correct proportions, stirring thoroughly to form a homogeneous mixture, and packing the mixture in a tubular cartridge, from which it can be forced through a nozzle as required, just prior to application.
 55. A cartridge when filled with a filler as claimed in claim 47 which further comprises a close fitting piston in the cartridge to the rear of the filler.
 56. A cartridge of filler as claimed in claim 55 which further includes means by which air under pressure can be applied to the rear of the piston to pressurise the material ahead of the piston, to force it through the nozzle.
 57. A method of filling a crack, gap or hole with filler from a tubular cartridge as claimed in claim 55 wherein the open end of the nozzle is located close to one end of the opening formed by a crack, gap or hole which is to be filled, and after pressurising the tube to cause the mixture of flexible caulk and particles to exit therefrom, the cartridge and nozzle is moved along the opening so that the mixture is forced therein.
 58. A method as claimed in claim 57 wherein, prior to the filling step, the opening is prepared, as by brushing and if necessary by gouging or routing, so as to widen the entrance to the opening to assist in filling it with the mixture.
 59. A method as claimed in claim 57 wherein the nozzle is positioned substantially perpendicular to the surface surrounding the opening which is to be filled, so that the mixture will tend to be forced deep into the opening.
 60. A method as claimed in claim 57 wherein the opening has a significant length such as a crack in rendering or a gap around a window or door frame, and the nozzle is held at an acute angle to the surface containing the opening so as to point away from the direction of movement of the nozzle along the length of the opening.
 61. Apparatus to enable the contents of a conventional acrylic caulk filled cartridge to be replaced by a filler mixture by which cracks, gaps or holes in masonry or a rendered finish on masonry can be filled prior to painting and comprising a mixture of an acrylic caulk and finely divided particulate material of a size to match the roughness of the surface around the crack, gap or hole, comprising a holder for supporting the cartridge, ejector means for forcing out the caulk contents of the cartridge into a container, means for adding particulate material to the caulk in the container, mixing means for mixing the caulk and particulate material to form a homogeneous mixture, withdraw means for removing the plunger from the cartridge, filling means for refilling the cartridge with at least some of the homogeneous mixture and insertion means for reinserting the plunger into the cartridge.
 62. Apparatus as claimed in claim 61 comprising a cartridge holder into which an acrylic caulk filled cartridge can be fitted, a cutting device for cutting off the sealed end of the nozzle, a push rod plunger and drive therefor adapted to act on a movable closure at the far end of the acrylic caulk filled cartridge to force the contents thereof through the nozzle, a first reservoir adapted to receive the ejected acrylic caulk, an elongate pin and drive therefor adapted to enter the nozzle after the cartridge has been emptied, to push the closure back along the cartridge and out of the said far end thereof, a second reservoir containing particulate material, mixing means for mixing the particulate material with the caulk in the first reservoir, a mixing aid such as a paddle or helical screw and a drive therefor to rotate the mixing aid in the first reservoir to thoroughly mix the acrylic caulk and the particulate material, and a feed by which the mixture is conveyed from the first reservoir to be forced into the open far end of the empty cartridge until it is full, insertion means for inserting the closure into the open end of the cartridge after it has been re-filled, and drive means to push the closure therealong until the contents are compacted and are ready for discharge through the nozzle.
 63. A method of mixing ingredients to form a flexible filler by which cracks, gaps or holes in masonry or a rendered finish can be filled prior to painting, and storing same ready for use, comprising the steps of removing acrylic caulk from a pre-filled cartridge thereof, mixing water with particulate material, mixing the caulk, water and particulate material to form a homogeneous mixture and refilling the cartridge therewith, for subsequent dispensing through a nozzle attached to the end of the cartridge.
 64. Apparatus for mixing ingredients in accordance with claim the method of 63 comprising a first reservoir for the caulk, a second reservoir of particulate material, a passage through which particulate material passes to be mixed with the caulk, a supply of water, a valve to control the flow of water into the second reservoir or into the passage and a region in which the caulk and particulate material are to be mixed, so that the particulate material is moistened before it is mixed with the caulk from the first reservoir, and a mixing aid to create a homogeneous mixture of the caulk and the particulate material.
 65. A method of mixing ingredients to form a flexible filler by which cracks, gaps or holes in masonry or a rendered finish on masonry can be filled prior to painting, and which comprises a mixture of an acrylic caulk and finely divided particulate material of a size to match the roughness of the surface around the crack, gap or hole, wherein water is supplied to a mixing region before, during or after the supply of particulate material thereto, a mixing aid therein is operated to mix the water and particulate material, whereafter acrylic caulk is introduced into the mixing region for mixing therewith, to form a homogeneous mixture prior to being loaded into an empty cartridge.
 66. A container filled with flexible filler by which cracks, gaps or holes in masonry or a rendered finish on masonry an be filled prior to painting, and comprising a mixture of an acrylic caulk and finely divided particulate material of a size to match the roughness of the surface around the crack, gap or hole, from which air is evacuated when it is sealed after filling (and resealed after use) to prevent the acrylic material from curing, as it will do if exposed to air.
 67. A container filled with flexible filler by which cracks, gaps or holes in masonry or a rendered finish on masonry can be filled prior to painting, and comprising a mixture of an acrylic caulk and finely divided particulate material of a size to match the roughness of the surface around the crack, gap or hole, comprising a squeezable tube which can be systematically squeezed to move the mixture from one end to the other, to mix the caulk and particulate material to a smooth paste prior to discharging the mixture for filling an opening.
 68. A flexible filler by which cracks, gaps or holes in masonry or a rendered finish on masonry can be filled prior to painting, which comprises a mixture of an acrylic caulk and finely divided particulate material of a size to match the roughness of the surface around the crack, gap or hole, wherein mixing the particulate material with the acrylic caulk bulks up the latter and results in a mixture having more body to it than does the basic acrylic caulk, so that the resulting mixture is thicker in consistency and will tend to remain where it is located in a crack, gap or hole. 